The present invention relates to an ink liquid supply system for an ink jet system printer of the charge amplitude controlling type and, more particularly, to a constant flow rate pump for use in the ink liquid supply system.
A constant flow rate ink liquid supply pump is essential and required in an ink jet system printer of the charge amplitude controlling type to ensure an accurate printing. The constant flow rate pump is effective not only to stabilize the ink liquid speed emitted from a nozzle but also to maintain the ink viscosity at a fixed value.
Accordingly, an object of the present invention is to provide a constant flow rate pump for use in an ink liquid supply system of an ink jet system printer of the charge amplitude controlling type.
Another object of the present invention is to provide a constant flow rate pump which is small in size.
Still another object of the present invention is to provide a small pump which integrally includes a pressure chamber for supplying the ink liquid to a nozzle and another pressure chamber for introducing waste ink liquid from a beam gutter of the ink jet system printer of the charge amplitude controlling type.
Yet another object of the present invention is to provide a novel ink liquid supply system in an ink jet system printer of the charge amplitude controlling type.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, a pump integrally includes three pressure chambers, which are divided by bellows and a three staged piston. The first pressure chamber functions to introduce the waste ink liquid collected by a beam gutter of the ink jet system printer of the charge amplitude controlling type. The second pressure chamber introduces the ink liquid from an ink liquid reservoir, and the third pressure chamber develops the ink liquid toward a nozzle of the ink jet system printer of the charge amplitude controlling type.
In a preferred form, a pressure accumulator is disposed between the outlet of the second pressure chamber and the inlet of the third pressure chamber in order to always maintain the pressure in the third pressure chamber higher than that in the second pressure chamber.